Explore the foundational principles and practical applications of hydrotherapy with “Rational Hydrotherapy: A Manual of the Physiological and Therapeutic Effects of Hydriatic Procedures, and the Technique of Their Application in the Treatment of Disease.” Written by the pioneering holistic health advocate John Harvey Kellogg, this comprehensive guide delves into the historical roots, scientific basis, and therapeutic benefits of water-based treatments. Discover the physics of water, air, heat, and light in therapy, alongside detailed examinations of anatomy, physiology, and hydrotherapy’s effects on circulation, skin, and the nervous system. Learn about various techniques for external and internal water applications and their impact on bodily functions. This essential manual provides a thorough understanding of hydrotherapy’s role in modern healthcare, offering insights into its application for diverse medical conditions. Ideal for health professionals and enthusiasts seeking in-depth knowledge of natural healing methods.